Steel Cord for Reinforcing Rubber Article, and Pneumatic Tire

Abstract

A steel cord for reinforcing a rubber article and a pneumatic tire. When it is a reinforcement material for a tire belt, the steel cord is capable of satisfying weight lightening, durability and driving stability. The steel cord comprises a core made by parallelly arranging two non-twisted core wires ( 1 ) from one layer of sheath made by twisting three to five sheath wires ( 2 ) around the core. The outline shape of the cord in a cross-section orthogonal to the axis of the cord is flat The inclination, as seen from the side of the cord, of the core wires is 3° or less relative to the cord axis.

1 . A steel cord for reinforcing a rubber article comprising: a core formed of two non-twisted core wires parallelly arranged in a longitudinal direction; and a single-layered sheath formed of three to five sheath wires twisted around said core, wherein the cord for reinforcing a rubber article has a flat outline shape in a cross section orthogonal to the cord axis and an inclination of the core wire, viewed from the side of the cord, is 3° or less with respect to a cord axis.  
   
   
       2 . The steel cord for reinforcing a rubber article according to  claim 1 , wherein said sheath wires are not uniformly dispersed around said core in arrangement but in uneven arrangement.  
   
   
       3 . The steel cord for reinforcing a rubber article according to  claim 1 , wherein tensile strength of said core wire and said sheath wire is 2.9 kN/mm 2  (300 kg/mm 2 ) or more.  
   
   
       4 . The steel cord for reinforcing a rubber article according to  claim 1 , wherein diameter of said core wire and said sheath wire is 0.21 mm to 0.24 mm.  
   
   
       5 . A pneumatic tire, wherein the steel cord for reinforcing a rubber article according to  claim 1  is used as a reinforcement material for belts.  
   
   
       6 . The pneumatic tire according to  claim 5 , wherein a lateral alignment of core wires of said steel cord for reinforcing the rubber article is along a width direction of the belt.